Lean and sustainability assessment in the sawmill industry using Sus-VSM: A case study in the context of Fiji

Waste from the perspective of lean manufacturing and sustainability has a huge influence on economic, environmental, and societal aspects. The inefficiency of the current manufacturing systems poses a huge risk to small and medium size sawmills going out of business as current prices of fossil fuel and associated emissions continue to rise at an alarming rate. In this case study, a local sawmill has been investigated to improve process efficiency using sustainable value stream mapping in the context of Fiji. The produced timber with the highest demand is selected as the product and a complete assessment is done on the downstream operation to compile data and develop the current state map. The current state map incorporates sustainability pillars to address the lacking factors such as energy and water consumption, raw material usage, labor physical load, and workspace noise level along with standard lean manufacturing time-based metrics. Sustainable value stream mapping allowed the research team along with a panel of experts to identify processor 2 as the root cause of bottlenecking, unnecessary material movement/transportation, and high physical load index score. Implementing a multi-blade horizontal bandsaw in place of processor 2 reduces; energy consumption for transport, energy consumption for processing, VAT, NVAT, process water consumption, raw material usage, and carbon emission by; 34.9%, 8.72%, 6.37%, 20%, 24.71%, 3.05%, and 10.33% respectively without compromising productivity. The findings of this research suggest evaluating and assessing sustainability performance using Sus-VSM in the sawmill industry unveils potential economic, environmental, and societal benefits.